The Preliminary Results for Atmospheric Parameters of the Candidate Ap Stars HD 90763 and HD 92728

Yıl 2018, Sayı: 2, 192 - 195, 19.08.2018

Asli Elmaslı Seyma Calıskan Kubraozge Unal

Öz

Chemical peculiar Ap stars show overabundances of
some metals, such as strontium, chromium, europium, praseodymium, and
neodymium. The rotations of these stars are much slower than those of normal
A-type stars. Another characteristic of Ap stars is that they have stronger
magnetic fields compared to classical A-type stars. We have selected the A-type
stars HD 90763 and HD 92728 to derive their atmospheric parameters. Both stars'
high-resolution spectra were obtained using the Coude Echelle Spectrograph
mounted on the 1.5 m Russian-Turkish Telescope at the TÜBİTAK National
Observatory, on the 23^rd of February, 2017. The wavelength range of
the spectra is from 3900 to 7900 Å. We followed the standard reduction
procedures for both stars and normalised the order covering the hydrogen beta
profile. We used ATLAS9 model atmospheres. The strontium 4215.519 Å line seen
in the spectra of HD 90763 and the neodymium 5102.428
Å line of HD 92728 were compared to the same lines of the normal A-type
star HD 187983. Sr line in HD 90763 and Nd line in HD 92728 are much stronger
than those of the normal A-type star. Thus, we suggest that HD 90763 and HD
92728 may be chemically peculiar Ap star candidates.

Anahtar Kelimeler

Ap stars, HD 90763, HD 92728

Kaynakça

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